Weight loss failure and proton pomp inhibitor (PPI)-resistant gastroesophageal reflux diseases (GERD) after sleeve gastrectomy (SG) are frequently encountered.The aim of this study was to evaluate the efficacy and risks of SG conversion to Roux-en-Y gastric bypass (RYGB) in the case of weight loss failure or severe GERD.University hospitals.Between March 2007 and December 2014, 34 patients with history of SG underwent RYGP. A retrospective analysis of a prospectively collected database was undertaken.Among 34 patients, 31 underwent revisional surgery for weight loss failure and 3 for PPI-resistant GERD. Six patients in the weight loss failure group had symptomatic GERD that was effectively treated with PPIs. The average body mass index (BMI) was 53±11 kg/m2 before SG. A laparoscopic approach was performed in 94% of patients. There was no postoperative mortality. Major adverse events (<90 days) occurred in 4 patients (11.7%). The mean length of stay was 6.7±2.8 days. At the time of revisional surgery, the mean BMI, percentage excess weight loss, and percentage weight loss were 44.7±9.8 kg/m2, 33.6±27.1%, and 16±9.7%, respectively, compared with 40.9±8.5 kg/m2, 63.1±36.2%, and 23.8±14% at 3 years. The GERD was resolved in all patients, allowing the cessation of PPI medication.Laparoscopic conversion of SG to RYGB is feasible and it allows improvement in secondary weight loss and GERD, but at the cost of high morbidity.